A prior art device for uniform distribution of lignite powder in a fluidized-ed lignite drier, is described in Luxembourg Patent LU-87 922 and corresponding U.S. patent application Ser. No. 870,626, now U.S. Pat. No. 5,273,148, the entire contents of which are incorporated herein by reference. In accordance with the device of Luxembourg Patent LU-87 922 a rotary cage supporting a chute with a variable angle of inclination is suspended from a peripheral annular ring of vertical axis. The peripheral edge of this ring is supported vertically and guided radially by wheels spaced circumferentially by an angle of 120.degree. C. on the support structure of the cage. This solution completely satisfies the above mentioned constructional constraints. The rolling surfaces of the wheels and the corresponding surfaces of the ring on which the wheels bear are, however, subjected to dry metal to metal contact and because of this undergo some degree of wear. The supporting and guiding wheels, as well as the peripheral annular ring, should therefore be considered as wear components which should be expected to be replaced regularly. This replacement naturally gives rise to labor and material costs and requires shutdowns of the installation.